Abstract: FOXP3 is a member of winged helix transcription family，specific expressed in CD4+CD25+Treg（regulatory T cell），which decide the development and function of Treg. The expression of Treg can prevent the immune surveillance of cancer，inhibits the effective immune reaction of tumor antigen，which makes FOXP3 become the study hotpot of tumor immune. In ovarian cancer， research says the high expression of FOXP3 is an independent prognostic factor of survival rate；In breast cancer，FOXP3 is a significant mark of tumor progression and metastasis，and it is the transcription inhibitor of breast cancer gene SKP2;While in cervical cancer，no matter in blood，cervical mucosa and cervical biopsy，it can all be tested highly expressed.

Key words: FOXP3, Autoimmunity, T-Lymphocytes, regulatory, Ovarian neoplasms, Uterine cervical neoplasms